Looking through the lists is it true that this iron has the highest MOI you have measured? What would it’s nearly 19 rating compare to a 15 rating?
The Mizuno JPX EZ from 2015-2016 does have one of the highest MOI’s we have measured. The main reason is the blade length. It has a long blade length and the C-Dimension is over 1.6″, which is a big contributor to the higher reading. MOI has an effect on the playability for sure, but it is not as much a factor as vertical cg or the horizontal cg (both of which do effect the MOI). I do not think most players would not notice a difference between a 15 MOI (which is still high and definitely above the average for irons) and a 19 MOI. I think they would notice performance difference between a 10 MOI and a 19 MOI. I could dig in and look, but basically irons will range from about 10 to 15 MOI, with some, like the JPX EZ going above that. Putters can range from below 10 to 95 MOI. A much larger spread with a much greater effect on performance.
Britt Lindsey
Done any robotic testing on off center impact performance with various MOI and MPF?
We have not done any robot testing in recent years. There have been tests done over the years that have always confirmed that the higher the MOI, the more stable the iron. Less distance is lost and dispersion is better the higher the MOI when the cg is in a “good” location. That means in a good horizontal location and a good vertical location. Ralph defined this in his book on Playability. Two studies done several decades ago showed similar results. One showed 25% increase in distance and 46% improvement in dispersion on off center hits with a higher MOI design vs. a lower MOI design. Another study showed that a “blade” design with an MOI of 10.9 ou/in2 had a 40% larger dispersion than a “cavity back” design with an MOI of 14.5 ou/in2.
So, we know that it makes a difference. Never a doubt. Defining exactly how much difference in MOI effects how much distance and dispersion, in modern iron designs, has not been done to my knowledge. I think the results would be similar to the stats I listed.
Britt Lindsey
Thank you
Thanks Britt!